Helle was a mortal in Greek mythology, who played an important part in the myth of Jason and the Argonauts, along with her twin brother Phrixus. She was the daughter of Athamas, king of Boeotia, and Nephele, a cloud nymph. She was the consort of the god Poseidon, with whom she had two children, Almops and Paeon.

Both siblings were hated by their stepmother Ino, who devised a plan to kill them. She destroyed the crops of the area, and when the locals asked an oracle for help, she bribed the messengers to say that the gods asked for Phrixus to be sacrificed. However, the twins' mother sent a flying golden ram to rescue her children. While on the air, Helle lost her grasp and fell into the sea, which was named Hellespont after her. Phrixus managed to reach the mythical land of Colchis where he was accepted by King Aeetes; to show his gratitude, Phrixus gifted the golden fleece of the ram to the king, which later became the artifact of desire for Jason and the Argonauts.